Photoaffinity labeling is an established approach to examine interactions between a ligand and a biological receptor, which relies on a photactivatable probe (a photolabel) to form a covalent bond between the ligand and the biological receptor upon irradiation, typically with ultra-violet (UV) light, of the ligand-receptor complex. Although many types of photoactivatable groups have been developed over the past 40 years, many suffer from, for example, cumbersome synthesis, instability in ambient light conditions, and limited aqueous solubility. As such, there exists a need for improved photolabels that can be used in photoaffinity labeling techniques.